I wrote a sudoku solver in Python as a little toy project, but wanted to make it feel a bit more real so I rewrote it in Javascript so that all the world can solve their sudokus.
If there is a solution, the program will find it. But beware: the method used is not very sophisticated, so if there not a solution, your browser might get upset while it searches through all the incorrect solutions.
See code on Github here.
Update: I also made an Android App of this – it was quite a challenge as I’m only very vaguely familiar with Java and had only once before played around with Android once a few years ago. There’s certainly room for improvement here, but I’m pleased to have made something that I can actually interact with on my phone. The code for this is also on the Github repo.